3io 



SULPHO-CARBOLA TES. 



reaction is much more manifest in the case of the 

 double acid than in the case of carbolic acid itself. 



The Sulpho-Carbolates are prepared from the pure 

 acid thus obtained by saturation with the various 

 oxides. 



Barium Sulpho-Carbolate, Ba (C 6 H 5 )SO 4 + 3Aq, is 

 prepared by adding to the sulpho-carbolicacid diluted 

 with ten times its bulk of water, barium carbonate. The 

 filtrate is to be slowly evaporated by heat, and allowed 

 to crystallise. The resulting barium sulpho-carbolate 

 is in colourless rhombic prisms, tending, like the other 

 sulpho-carbolates, to cohere in spheroidal groups. 

 It is very readily soluble in water and in alcohol. 



Sodium Sulpho-Carbolate, Na(C 6 H 5 )SO 4 + Aq, is 

 obtained by carefully neutralizing the pure sulpho- 

 carbolic acid dissolved in at least six volumes 'of 

 water with carbonate of sodium or caustic soda. 

 The resulting solution should be slowly evaporated 

 over a sand-bath or water-bath until a pellicle appears 

 upon the surface ; it should be then set aside to 

 crystallise. 



The resulting salt is in brilliant, colourless, rhombic 

 prisms, having the characteristic tendency to cohere 

 in rosettes, freely soluble in six times its bulk of cold 

 distilled water, and in two-thirds its weight of boiling 

 water ; it is slightly soluble in alcohol, but not in 

 ether. A strong heat drives off a portion of the car- 

 bolic acid, and an aqueous solution of the residue 

 gives the reactions of sulphuric acid ; at a red heat it 



